My girlfriend just upgraded from an S3 to an S5. Since then, the call quality on my end has been extremely bad. She is almost not understandable at times. This is worse when she calls my cell phone, but also happens on land lines. Not having had a chance to look in to this issue, I was curious if there were any settings that could possibly remedy this. I'll be seeing her in a couple days, and want to swap phones with her and let her hear what I'm hearing. However, if there is an easy fix I would like to be able to implement it then.
I'm not sure if root has been gained on this phone, but I'm pretty sure that she wouldn't be terribly interested in rooting or doing any other serious modifications. If this is an issue nobody else has, I'll probably suggest she take the phone back and get a new one.
Any help would be appreciated.